I would not suggest that Donald Trump and Ivan the Terrible are that similar, but reading the US president’s frankly rather bizarre letter to Nancy Pelosi about impeachment, I was struck by a similarity.

In 1564, Tsar Ivan IV, Grozny (usually translated as ‘Terrible’ although ‘Awesome’ or ‘Dread’ are probably more accurate) upped sticks from Moscow and headed for the fortified village of Alexandrova Sloboda, writing a letter to the boyars, the aristocrats, in which he savaged them for their purported (and probably real) embezzlement, vindictiveness and disrespect. He made a great show of abdicating the throne.

This was a calculated and cunning gamble. His relationship with the boyars had been rocky to say the least: he mistrusted them deeply (and in fairness probably with good reason), but also needed them to manage his country for him. He wanted not to destroy but to break them. Many may have viewed Ivan’s departure with a certain relief at first, but it soon became clear that they could not do without him. They had no spare tsar in reserve, and an angry Moscow mob was looking ready for some lynchings. So in 1565 they capitulated, begging Ivan to return, and in effect granting him everything he wanted: his own kingdom-within-a-kingdom, the Oprichnina, and the power of life or death over his nobility.

In a way – in a way – the other letter may be read the same way. Sure, in part it is a semi-coherent sermon of spleen, a Trump twitter-thread’s big brother. Whatever his tenuous relationship with manners and grammar, though, he clearly does have a certain visceral political savvy. I read his letter as being in part, and in a way, a similar message: warning his boyars – the powers in the Republican Party – that they have no obvious Trump-substitute in the wings (VP Mike Pence was in that respect well-chosen as someone who scares even many of them), and that if they were not wholly and full-throatedly supportive of the president, they faced today’s answer to the Moscow mob, the rabid Trump base, who may be a minority, but are a loud, active, vindictive and effective one.

From fur robes to red ties, politics really doesn’t change all that much.